Aliphatic polycarbonate resin, partition material, substrate and production method therefor, production method for wiring substrate, and wiring forming method

ABSTRACT

Provided is an aliphatic polycarbonate resin having excellent water repellency. Also provided are a partition material, a substrate and a method for producing the same, a method for producing a wiring substrate, and a wiring forming method. 
     The aliphatic polycarbonate resin of the present invention comprises a structural unit represented by the following formula (1): 
                         
wherein R 1 , R 2 , and R 3  are each independently a hydrogen atom, a C 1 -C 10  alkyl group, or a C 6 -C 20  aryl group; X is a substituent having a fluorine atom; and R 1 , R 2 , and R 3  may be the same or different; and
         the aliphatic polycarbonate resin has a contact angle against water of 90° or more.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/JP2017/014170 filed Apr. 5, 2017, claiming priority based onJapanese Patent Application No. 2016-077960 filed Apr. 8, 2016.

TECHNICAL FIELD

The present invention relates to an aliphatic polycarbonate resin, apartition material, a substrate and a method for producing the same, amethod for producing a wiring substrate, and a wiring forming method.

BACKGROUND ART

Aliphatic polycarbonate resins synthesized from raw materials containingcarbon dioxide and epoxy compounds have been actively studied in recentyears in terms of recycling carbon dioxide, and various applicationsthereof have been found. Since aliphatic polycarbonate resins havecharacteristically low thermal decomposition temperatures, theirapplication to ceramic binders and metal ink by taking advantage of thischaracteristic has been examined (e.g., PTL 1 and PTL 2). Moreover,because aliphatic polycarbonate resins can be easily removed by heatingor short-wavelength light (e.g., irradiation with vacuum ultravioletrays or soft X-rays), the use of aliphatic polycarbonate resins aspartition material positive resist resins has also been examined (e.g.,PTL 3 and PTL 4). Thus, due to the use of aliphatic polycarbonate resinsas partition material positive resist resins, wiring substrates to beincorporated into electronic components etc. can be produced. Forexample, a partition pattern is formed on a substrate using an aliphaticpolycarbonate resin, and a groove is formed by photolithography or thelike. Then, a wiring material containing, for example, metal ink isprovided in the groove. Subsequently, sintering is performed to removethe aliphatic polycarbonate resin, and curing and sintering of the inkproceed. A wiring substrate is formed in this manner.

CITATION LIST Patent Literature

PTL 1: JPH06-334282A

PTL 2: JP2014-055232A

PTL 3: JP2010-106286A

PTL 4: JP2015-197519A

SUMMARY OF INVENTION Technical Problem

When a wiring substrate is produced using a substrate having a partitionpattern made of an aliphatic polycarbonate resin as described above,water-based ink is often used as the ink that is a wiring material. Thisis because there is a possibility that the aliphatic polycarbonate resinmay be dissolved and swollen in an organic solvent, and it is thusnecessary to avoid collapse etc. of the partition.

However, conventional aliphatic polycarbonate resins (e.g.,polypropylene carbonate resins) have low water repellency; thus, whenink was placed on a substrate by ink immersion or the like, the ink wasalso likely to be placed on the aliphatic polycarbonate resin, which wasa partition material. Therefore, in the production of wiring substrates,it was difficult to allow the ink to remain only in the groove, and itwas difficult to form desired wiring patterns with high accuracy. Fromthis viewpoint, there has been a demand for the development of aliphaticpolycarbonate resins having more excellent water repellency thanconventional resins.

The present invention was made in view of the above circumstances. Anobject of the present invention is to provide an aliphatic polycarbonateresin having excellent water repellency. Another object of the presentinvention is to provide a partition material, a substrate and a methodfor producing the same, a method for producing a wiring substrate, and awiring forming method.

Solution to Problem

The present inventors conducted extensive research to achieve the aboveobjects, and consequently found that the above objects can be achievedby an aliphatic polycarbonate resin having a repeating structural unitwith a specific structure. Thus, the present invention has beencompleted.

Specifically, the present invention includes, for example, the mainsubjects described in the following items.

Item 1. An aliphatic polycarbonate resin comprising a structural unitrepresented by the following formula (1):

wherein R¹, R², and R³ are each independently a hydrogen atom, a C₁-C₁₀alkyl group, or a C₆-C₂₀ aryl group; X is a substituent having afluorine atom; and R¹, R², and R³ may be the same or different; and

the aliphatic polycarbonate resin having a contact angle against waterof 900 or more.

Item 2. The aliphatic polycarbonate resin according to Item 1, wherein Xis a group containing a trifluoromethyl group.

Item 3. The aliphatic polycarbonate resin according to Item 1 or 2,wherein the structural unit represented by the formula (1) is containedin an amount of 0.05 to 5 mol % based on the total number of moles ofall structural units.

Item 4. The aliphatic polycarbonate resin according to any one of Items1 to 3, further comprising a structural unit represented by thefollowing formula (2):

wherein R⁴, R⁵, R⁶, and R⁷ are each independently a hydrogen atom, aC₁-C₁₀ alkyl group, or a C₆-C₂₀ aryl group; and R⁴, R⁵, R⁶, and R⁷ maybe the same or different.

Item 5. The aliphatic polycarbonate resin according to any one of Items1 to 4, which is an aliphatic polycarbonate resin for partitionformation.

Item 6. A partition material comprising the aliphatic polycarbonateresin according to Item 5.

Item 7. A substrate having a partition made of the aliphaticpolycarbonate resin according to Item 5.

Item 8. A method for producing the substrate according to Item 7, themethod comprising providing a coating film of a partition materialcomprising the aliphatic polycarbonate resin to form a partition.

Item 9. A method for producing a wiring substrate using the substrateaccording to Item 7, the method comprising providing a wiring materialon the substrate to form wiring.

Item 10. The method for producing a wiring substrate according to Item9, the method comprising forming a groove in the substrate, andproviding a wiring material in the groove to form wiring.

Item 11. A wiring forming method comprising forming wiring using thepartition material according to Item 6.

Advantageous Effects of Invention

The aliphatic polycarbonate resin according to the present invention haswater-repellent performance superior to that of conventionally knownaliphatic polycarbonate resins. Therefore, for example, when a partitionis formed using the aliphatic polycarbonate resin of the presentinvention as a partition material, water-based ink is allowed to remainonly in a desired portion with high accuracy.

Because the partition material according to the present inventioncontains the above polycarbonate resin, a partition that allowswater-based ink to remain only in a desired portion with high accuracycan be formed.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention are described in detail below. Inthe present specification, the terms “comprise” and “contain” includethe concepts of “comprise,” “contain,” “substantially consist of,” and“consist of.”

The aliphatic polycarbonate resin of the present embodiment contains astructural unit represented by the following formula (1):

wherein R¹, R², and R³ are each independently a hydrogen atom, a C₁-C₁₀alkyl group, or a C₆-C₂₀ aryl group; X is a substituent having afluorine atom; and R¹, R², and R³ may be the same or different; and

the aliphatic polycarbonate resin has a contact angle against water of90° or more.

Due to the structural unit having the specific structure, the abovealiphatic polycarbonate resin has water-repellent performance superiorto that of conventional aliphatic polycarbonate resins. Therefore, forexample, when the aliphatic polycarbonate resin is used as a partitionmaterial to form a partition, water-based ink is allowed to remain onlyin a desired portion with high accuracy.

In the formula (1), the type of C₁-C₁₀ alkyl group as R¹, R², and R³ maybe linear or branched, and the alkyl group may have one or moresubstituents. Specific examples of the C₁-C₁₀ alkyl group includemethyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl,n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups.

The above alkyl group more preferably has 1 to 4 carbon atoms.

In the formula (1), the C₆-C₂₀ aryl group as R¹, R², and R³ may besubstituted or unsubstituted. Specific examples of the aryl groupinclude phenyl, tolyl, indenyl, naphthyl, and tetrahydronaphthyl groups.

The above aryl group more preferably has 6 to 14 carbon atoms.

X, which is a substituent having a fluorine atom, may be a fluorine atomor a group containing a fluorine atom. X as a group containing afluorine atom is, for example, a C₁-C₁₀ fluoroalkyl group, a C₁-C₁₀perfluoroalkyl group, a C₁-C₁₀ fluoroalkoxy group, a C₁-C₁₀perfluoroalkoxy group, a C₆-C₂₀ fluoroaryl group, or a C₆-C₂₀perfluoroaryl group.

The number of fluorine atoms that constitute a C₁-C₁₀ fluoroalkyl groupmay be only one or may be two or more. Examples of the C₁-C₁₀fluoroalkyl group include groups in which some hydrogen atoms of theC₁-C₁₀ alkyl groups mentioned above are replaced by fluorine atoms.

The number of fluorine atoms that constitute a C₁-C₁₀ fluoroalkoxy groupmay be only one or may be two or more. Examples of the C₁-C₁₀fluoroalkoxy group include groups in which some hydrogen atoms ofmethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy,tert-butoxy, or the like are replaced by fluorine atoms.

The number of fluorine atoms that constitute a C₆-C₂₀ fluoroaryl groupmay be only one or may be two or more. Examples of the C₆-C₂₀ fluoroarylgroup include groups in which some hydrogen atoms of the C₆-C₂₀ arylgroup mentioned above are replaced by fluorine atoms.

X as a substituent having a fluorine atom may contain an ether group, anester group, a carbonate group, an amino group, an amide group, acarbonyl group, etc.

X as a substituent having a fluorine atom is preferably a groupcontaining a trifluoromethyl group (CF₃—). It is assumed that when atrifluoromethyl group is contained, the trifluoromethyl group with lowsurface free energy is easily segregated to the uppermost surface. Thewater repellency of the aliphatic polycarbonate resin can be therebyfurther improved.

The aliphatic polycarbonate resin of the present embodiment may consistof the structural unit represented by the formula (1), or may compriseother structural units other than the structural unit represented by theformula (1).

In the aliphatic polycarbonate resin of the present embodiment, thecontent of the structural unit represented by the formula (1) ispreferably 5 mol % or less, and more preferably 0.05 mol % or more,based on the total number of moles of all structural units. In thiscase, the polymerization reactivity in the production of the aliphaticpolycarbonate resin, and the solubility of the aliphatic polycarbonateresin in solvents are improved, and desired water repellency tends to beeasily obtained. In the aliphatic polycarbonate resin of the presentembodiment, the content of the structural unit represented by theformula (1) is more preferably 2 mol % or less based on the total numberof moles of all structural units. Moreover, in the aliphaticpolycarbonate resin of the present embodiment, the content of thestructural unit represented by the formula (1) is more preferably 0.1mol % or more based on the total number of moles of all structuralunits.

The aliphatic polycarbonate resin of the present embodiment may furthercontain a structural unit represented by the following formula (2):

wherein R⁴, R⁵, R⁶, and R⁷ are each independently a hydrogen atom, aC₁-C₁₀ alkyl group, or a C₆-C₂₀ aryl group; and R⁴, R⁵, R⁶, and R⁷ maybe the same or different.

In the formula (2), the C₁-C₁₀ alkyl group and C₆-C₂₀ aryl group as R⁴,R⁵, R⁶, and R⁷ are the same as the C₁-C₁₀ alkyl group and C₆-C₂₀ arylgroup as R¹, R², and R³ of the formula (1), respectively. The alkylgroup as R⁴, R⁵, R⁶, and R⁷ more preferably has 1 to 4 carbon atoms. Thearyl group as R⁴, R⁵, R⁶, and R⁷ more preferably has 6 to 14 carbonatoms.

In the aliphatic polycarbonate resin of the present embodiment, thecontent of the structural unit represented by the formula (2) ispreferably 95 mol % or more, and more preferably 98 mol % or more, basedon the total number of moles of all structural units. In this case, thealiphatic polycarbonate resin has excellent water repellency.

The mass average molecular weight of the aliphatic polycarbonate resinof the present embodiment is preferably 50000 or more, and morepreferably 100000 or more, in terms of rectangular shape-retaining powerwhen used as a partition material. Moreover, in terms of avoiding thereduction in handling properties due to the decrease in the solubilityof the aliphatic polycarbonate resin in solvents, the mass averagemolecular weight of the aliphatic polycarbonate resin is preferably 1million or less, and more preferably 500000 or less.

The contact angle of the aliphatic polycarbonate resin of the presentembodiment against water is 900 or more. In this case, the aliphaticpolycarbonate resin exhibits desired water repellency. The contact angleof the aliphatic polycarbonate resin against water is preferably 95° ormore. The above contact angle is generally less than 1800 (e.g., lessthan 1500).

The contact angle as mentioned in the present specification is definedby a value measured in the following manner. First, the aliphaticpolycarbonate resin of the present embodiment is dissolved in acetone sothat the concentration is 2.5 mass %, and a glass substrate is immersedin the obtained solution. Then, the glass substrate (glass substrate inwhich the solution is attached to the surface thereof) removed from thesolution is dried at 25° C. for 24 hours to thereby prepare a sample forcontact angle measurement. A drop of distilled water is dropped on theobtained measurement sample by a microsyringe so that the dropletdiameter is 2 mm, and the contact angle is measured. This measurement isperformed in an environment at a temperature of 25° C. and a humidity RHof 50%. The contact angle can be measured using a commercially availablecontact angle meter.

The aliphatic polycarbonate resin of the present embodiment may containother types of polycarbonate resin and other resin components within arange that does not impair the effects of the present invention.

The aliphatic polycarbonate resin of the present embodiment can be used,for example, after dissolution in a solvent that can dissolve thealiphatic polycarbonate resin.

Examples of the solvent that can dissolve the aliphatic polycarbonateresin include toluene, ethyl acetate, butyl acetate, isopropyl alcohol,methyl isobutyl ketone, acetone, methyl ethyl ketone,N-methyl-2-pyrrolidone, ethylene glycol ethyl ether, ethylene glycolmonobutyl ether, ethylene glycol monoethyl ether acetate, diethyleneglycol monoethyl ether, diethylene glycol monomethyl ether, diethyleneglycol monoisobutyl ether, trimethyl pentanediol monoisobutyrate, ethylcarbitol, butyl carbitol, ethyl carbitol acetate, butyl carbitolacetate, terpineol, terpineol acetate, dihydro terpineol, dihydroterpineol acetate, texanol, isophorone, butyl lactate, dioctylphthalate, dioctyl adipate, benzyl alcohol, phenylpropylene glycol,cresol, N,N-dimethylformamide, propylene carbonate, and the like. Ofthese, N-methyl-2-pyrrolidone, terpineol, terpineol acetate, ethylcarbitol acetate, butyl carbitol acetate, texanol, and propylenecarbonate are preferable, because they have a moderately high boilingpoint and are likely to be uniformly volatilized during sintering. Theseorganic solvents may be used singly or in combination of two or more.

The amount of the above solvent to be used (blended) is preferably 100to 2000 parts by mass, more preferably 200 to 1500 parts by mass, andeven more preferably 300 to 1000 parts by mass, based on 100 parts bymass of the aliphatic polycarbonate resin, in terms of ease of handlingof a solution to be obtained (a solution of the aliphatic polycarbonateresin of the present invention).

Examples of the method for producing the aliphatic polycarbonate resinof the present embodiment include a method of subjecting an epoxide andcarbon dioxide to a polymerization reaction in the presence of a metalcatalyst.

By selecting the type of epoxide, an aliphatic polycarbonate resinhaving the structural unit represented by the formula (1), and furtheroptionally having the structural unit represented by the formula (2),can be obtained.

Examples of the epoxide used to form the structural unit represented bythe formula (1) include epoxides represented by the following formula(3):

wherein R⁸ is a fluorine atom or a monovalent organic group containing afluorine atom, and Q is a single bond or a divalent linking group thatdoes not contain a fluorine atom.These epoxides may be used singly or in combination of two or more.

In the formula (3), the Q-R⁸ portion corresponds to X in the formula(1).

When R⁸ is a monovalent organic group containing a fluorine atom,examples of R⁸ include fluoroalkyl groups, such as monofluoromethyl,difluoromethyl, 2,2,2-trifluoroethyl, and1,1,1-3,3,3-hexafluoroisopropyl; perfluoroalkyl groups, such astrifluoromethyl, pentafluoroethyl, perfluoropropyl, and perfluorobutyl;fluoroaryl groups, such as 4-fluorophenyl, 2,6-difluorophenyl, and2,4,6-trifluorophenyl; perfluoroaryl groups, such as pentafluorophenyland perfluoronaphthyl; and the like.

In the formula (3), when Q is a divalent linking group that does notcontain a fluorine atom, Q is preferably an alkylene group, or analkylene group containing an ether oxygen atom, an ester group, acarbonate group, an amino group, an amide group, or a carbonyl group;and more preferably an alkylene group or an alkylene group containing anether oxygen atom. The alkylene group is preferably a linear alkylenegroup having one or more carbon atoms, such as a methylene group(—CH₂—), an ethylene group (—CH₂CH₂—), or a propylene group(—CH₂CH₂CH₂—); and particularly preferably a C₁-C₅ linear alkylenegroup. The alkylene group containing an ether oxygen atom is preferablya group in which an oxygen atom is inserted between the carbons of theabove alkylene group, or a group in which an oxygen atom is insertedinto the terminal part of the alkylene group (terminal part on the R⁹side); and more preferably a group in which an oxygen atom bonds to theterminal part of a C₁-C₄ linear alkylene group (terminal part on the R⁸side), or a group in which an oxygen atom is inserted into 1 or 2portions between the carbons of a C₂-C₄ linear alkylene group (e.g.,—CH₂O—, —CH₂OCH₂—, or —CH₂OCH₂CH₂—).

In the formula (3), when Q is a single bond, R⁸ directly bonds to thecarbon atom of the epoxy group.

Examples of the epoxide used to form the structural unit represented bythe formula (2) include ethylene oxide, propylene oxide, 2-butene oxide,and isobutylene oxide. Of these, ethylene oxide and propylene oxide arepreferable because they have high reactivity. These epoxides may be usedsingly or in combination of two or more.

Examples of the metal catalyst include zinc-based catalysts,aluminum-based catalysts, chromium-based catalysts, cobalt-basedcatalysts, and the like. Of these, zinc-based catalysts are preferable,because they have high polymerization activity and wide substrateversatility in the polymerization reaction between an epoxide and carbondioxide.

Examples of zinc-based catalysts include organozinc catalysts, such aszinc acetate, diethyl zinc, and dibutyl zinc; organozinc catalystsobtained by reaction of zinc compounds and compounds such as primaryamine, divalent phenol (benzenediol), aromatic dicarboxylic acid,aromatic hydroxy acid, aliphatic dicarboxylic acid, or aliphaticmonocarboxylic acid; and the like. Of these organozinc catalysts,organozinc catalysts obtained by reaction of zinc compounds, aliphaticdicarboxylic acid, and aliphatic monocarboxylic acid are preferablebecause they have higher polymerization activity; and organozinccatalysts obtained by reaction of zinc oxide, glutaric acid, and aceticacid are more preferable.

A reaction solvent may be used for the polymerization reaction, ifnecessary. Various organic solvents can be used as the reaction solvent.Examples of organic solvents include aliphatic hydrocarbon-basedsolvents, such as pentane, hexane, octane, decane, and cyclohexane;aromatic hydrocarbon-based solvents, such as benzene, toluene, andxylene; halogenated hydrocarbon-based solvents, such as methylenechloride, chloroform, carbon tetrachloride, 1,1-dichloroethane,1,2-dichloroethane, ethyl chloride, trichloroethane, 1-chloropropane,2-chloropropane, 1-chlorobutane, 2-chlorobutane,1-chloro-2-methylpropane, chlorobenzene, and bromobenzene; ether-basedsolvents, such as dimethoxyethane, tetrahydrofuran,2-methyltetrahydrofuran, 1,4-dioxane, and 1,3-dioxolane; ester-basedsolvents, such as ethyl acetate, n-propyl acetate, and isopropylacetate; amide-based solvents, such as N,N-dimethylformamide andN,N-dimethylacetamide; carbonate-based solvents, such as dimethylcarbonate, ethylmethyl carbonate, diethyl carbonate, and propylenecarbonate; and the like. These organic solvents may be used singly or incombination of two or more.

The amount of the reaction solvent to be used is preferably 100 to 10000parts by mass based on 100 parts by mass of the epoxide, in terms ofsmoothly promoting the reaction.

The method for subjecting an epoxide and carbon dioxide to apolymerization reaction in the presence of a metal catalyst is notparticularly limited. For example, an epoxide and a metal catalyst, andoptionally a co-catalyst, a reaction solvent, etc., are placed in anautoclave, and then mixed; then, carbon dioxide is injected into theautoclave to perform the reaction.

The amount of carbon dioxide used in the polymerization reaction ispreferably 1 to 10 mol, more preferably 1 to 5 mol, and even morepreferably 1 to 3 mol, per mol of epoxide.

The operating pressure of carbon dioxide used in the polymerizationreaction is preferably 0.1 MPa or more, more preferably 0.2 MPa or more,and even more preferably 0.5 MPa or more, in terms of smoothly promotingthe reaction, and is preferably 20 MPa or less, more preferably 10 MPaor less, and even more preferably 5 MPa or less, in terms of obtainingeffects commensurate with the operating pressure.

The polymerization reaction temperature is preferably 0° C. or more,more preferably 10° C. or more, and even more preferably 20° C. or more,in terms of shortening the reaction time, and is preferably 100° C. orless, more preferably 90° C. or less, and even more preferably 80° C. orless, in terms of preventing side reactions and improving the yield.

The polymerization reaction time varies depending on the polymerizationreaction conditions and cannot be generally determined; however, thepolymerization reaction time is generally about 1 to 40 hours.

The above aliphatic polycarbonate resin can be used for variousapplications.

For example, the aliphatic polycarbonate resin of the present embodimentcan be used as an aliphatic polycarbonate resin for forming partitions(aliphatic polycarbonate resin for partition formation), that is, aconstituent of a partition material.

The partition material contains the above aliphatic polycarbonate resin,and may contain other components. Examples of other components includesolvents, binders, light stabilizers, sensitizing agents,photosensitizers, and the like that are conventionally used forpartition materials. As the type of solvent, for example, solventsconventionally used as partition materials can be used.

When the partition material of the present embodiment contains a solventin addition to the aliphatic polycarbonate resin, the content of thealiphatic polycarbonate resin can be 5 to 30 parts by mass based on 100parts by mass of the solvent.

A substrate having a partition made of the aliphatic polycarbonate resinof the present invention can be obtained by forming a partition patternwith a desired shape on a substrate using the above partition material.Such a partition can be formed, for example, with a coating film of thepartition material containing the aliphatic polycarbonate resin of thepresent invention.

When the above partition material is used, a partition that allowswater-based ink to remain only in a desired portion with high accuracycan be formed, because the partition material contains the aliphaticpolycarbonate resin. Therefore, according to the partition material, forexample, a wiring substrate having a wiring pattern controlled with highprecision can be formed. That is, because a partition made of the abovepartition material has high water repellency, when water-based ink isplaced on a substrate in which such a partition is formed, thewater-based ink is less likely to be placed on the partition. This makesit possible to form a desired wiring pattern with high precision.

Accordingly, the partition material is suitable as a material forforming fine wiring controlled with high precision.

As the method for producing a substrate having a partition made of apartition material containing the aliphatic polycarbonate resinaccording to the present invention, for example, the above substrate canbe produced by a method comprising providing a coating film of thepartition material containing the aliphatic polycarbonate resin to forma partition.

Specifically, a substrate for forming a partition pattern is firstprepared, and a liquid partition material is applied to a predeterminedportion of the substrate surface. Subsequently, heat-treatment orirradiation with ultraviolet rays etc. is optionally performed to form acoating film of the partition material containing the polycarbonateresin of the present invention, thereby forming a partition pattern. Asubstrate having a partition can thereby be formed.

The portions in which the coating film of the partition materialcontaining the polycarbonate resin of the present invention is formedcan be, for example, a portion in which a wiring pattern is planned tobe formed on the substrate surface, and the periphery thereof.

As the type of substrate, for example, substrates conventionally used toform wiring substrates, such as electronic substrates, can be used.

When the above substrates are used, wiring substrates that can beincorporated into various electronic components etc. can be produced.

As the method for producing a wiring substrate, for example, the wiringsubstrate can be produced by a method comprising providing a wiringmaterial on the substrate to form wiring. More specifically, the wiringsubstrate can be produced by a production method comprising forming agroove in the substrate, and providing a wiring material in the grooveto form wiring.

The above groove can be formed, for example, by photolithography or likemethod. The groove formation method may be other conventionally usedmethods. The groove may be formed so that the shape thereof is the sameas the shape of the target wiring pattern.

As the method for providing a wiring material in the groove formed asdescribed above, for example, a method of pouring the wiring materialinto the groove can be used. Examples of the method for pouring thewiring material into the groove include a method to immerse thesubstrate in which a groove is formed in a liquid wiring material, amethod to apply a liquid wiring material to the substrate in which agroove is formed, and a method to inkjet-print a wiring material on thesubstrate in which a groove is formed.

Alternatively, the wiring substrate can be produced by a methodcomprising applying a wiring material to the substrate byinkjet-printing or the like to form wiring, without forming a groove inthe substrate.

The type of wiring material is not particularly limited. For example,water-based ink, such as metal ink, conventionally used to form wiringcan be used.

In the above substrate, a partition made of the aliphatic polycarbonateresin mentioned above is formed. Because this partition has excellentwater repellency, the wiring material is allowed to remain only in adesired groove with high accuracy.

After the wiring material is provided on the substrate as describedabove, the substrate is heated at a temperature in which the wiringmaterial is sintered, thereby firing the wiring material to form wiring.The sintering temperature can be suitably set depending on the type ofwiring material used. As a result of the above sintering treatment, thealiphatic polycarbonate resin that forms the partition pattern is burnedaway.

The wiring substrate is produced through the above sintering treatment.Because the wiring pattern of the wiring substrate formed in this manneris controlled with high precision, it is possible to significantlyimprove the performance of electronic components etc.

As described above, according to the wiring forming method using thepartition material containing the above aliphatic polycarbonate resin,fine wiring can be formed with high accuracy by a simple method, andthis method is useful as a method for constructing various electroniccomponents.

EXAMPLES

The present invention is described in more detail below with referenceto Examples.

In the Examples and Comparative Example, the physical properties wereevaluated by the methods shown below.

Mass Average Molecular Weight (Mw) of Aliphatic Polycarbonate Resin

An N,N-dimethylformamide solution with an aliphatic polycarbonate resinconcentration of 0.5 mass % was prepared, and subjected to measurementby high-performance liquid chromatography. After measurement, the massaverage molecular weight of the aliphatic polycarbonate resin wasdetermined by comparison with polystyrene with known mass averagemolecular weight measured under the same conditions. The measurementconditions were as follows:

Column: GPC column (trade name: Shodex OHPac SB-800 series, produced byShowa Denko K.K.)

Column temperature: 40° C.

Eluent: 0.03 mol/L lithium bromide-N,N-dimethylformamide solution

Flow rate: 0.65 mL/min

Contact Angle of Aliphatic Polycarbonate Resin

An aliphatic polycarbonate resin was dissolved in acetone so that theresin concentration was 2.5 mass %, and a glass substrate was immersedin the obtained solution. Thereafter, the glass substrate was removedfrom the solution, and dried at 25° C. for 24 hours, thereby producing aglass substrate coated with the aliphatic polycarbonate resin. A drop ofdistilled water was dropped on the glass substrate by a microsyringe sothat the droplet diameter was 2 mm, and the contact angle was visuallymeasured with a contact angle meter (“CA-S 150,” produced by KyowaInterface Science Co., Ltd.). This measurement was performed in anenvironment at a temperature of 25° C. and a humidity RH of 50%.

Thermal Decomposition Starting Temperature of Aliphatic PolycarbonateResin

The thermal decomposition starting temperature was measured by“TG/DTA7220” (produced by Hitachi High-Tech Science Corporation) in anitrogen atmosphere while increasing the temperature from roomtemperature to 500° C. at a heating rate of 10° C./min. The thermaldecomposition starting temperature was the intersection of a lineparallel to the horizontal axis passing through the mass before thestart of test heating, and a tangent line drawn so that the gradientbetween the bending points in the decomposition curve was the maximum.

Production Example 1: Production of Organozinc Catalyst

In a 0.3-L four-necked flask equipped with a stirrer, a nitrogen gasintroducing tube, a thermometer, a Dean-Stark tube, and a refluxcondenser tube, 7.73 g (95 mmol) of zinc oxide, 12.3 g (100 mmol) ofglutaric acid, 0.114 g (2 mmol) of acetic acid, and 76.0 g of toluenewere placed. Next, while flowing nitrogen at a flow rate of 50 mL/min inthe reaction system, the temperature was increased to 55° C., and themixture was reacted by stirring at this temperature for 4 hours.Thereafter, the temperature was increased to 110° C., and azeotropicdehydration was performed by stirring at this temperature for 2 hours toremove water. Then, the reactant was cooled to room temperature, therebyobtaining a slurry liquid containing an organozinc catalyst.

Example 1

After the internal system of a 1-L autoclave equipped with a stirrer, agas introducing tube, and a thermometer was previously replaced by anitrogen atmosphere, 39.1 g of the slurry liquid containing anorganozinc catalyst (45 mmol) obtained in Production Example 1, 192.4 gof dimethyl carbonate, 26.1 g (450 mmol) of propylene oxide, and 12.8 g(26.9 mmol) of(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl)oxirane wereplaced therein. Next, the temperature was increased to 60° C. whilestirring. Then, carbon dioxide was added until the internal pressure ofthe reaction system was 1.0 MPa. The polymerization reaction was carriedout for 10 hours while supplying carbon dioxide consumed by thereaction. After completion of the reaction, the autoclave was cooled anddepressured, followed by filtration and then vacuum-drying, therebyobtaining 38.6 g of aliphatic polycarbonate resin. The mass averagemolecular weight of the obtained aliphatic polycarbonate resin was354000 (Mw/Mn=7.44), and the content of the structural unit representedby the formula (1) in the aliphatic polycarbonate resin was 1.0 mol %.

Example 2

Polymerization was carried out in the same manner as in Example 1,except that 12.8 g of(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl) oxirane waschanged to 2.9 g (6.9 mmol) of3-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyloxy)-1,2-epoxypropane,thereby obtaining 41.0 g of aliphatic polycarbonate resin. The massaverage molecular weight of the obtained aliphatic polycarbonate resinwas 473000 (Mw/Mn=8.13), and the content of the structural unitrepresented by the formula (1) in the aliphatic polycarbonate resin was0.2 mol %.

Example 3

Polymerization was carried out in the same manner as in Example 2,except that the amount of3-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyloxy)-1,2-epoxypropane waschanged to 4.5 g (10.8 mmol), thereby obtaining 34.6 g of aliphaticpolycarbonate resin. The mass average molecular weight of the obtainedaliphatic polycarbonate resin was 330000 (Mw/Mn=10.73), and the contentof the structural unit represented by the formula (1) in the aliphaticpolycarbonate resin was 1.2 mol %.

Comparative Example 1

Polymerization was carried out in the same manner as in Example 1,except that 12.8 g of(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl) oxirane was notused, thereby obtaining 40.0 g of aliphatic polycarbonate resin. Themass average molecular weight of the obtained aliphatic polycarbonateresin was 301000 (Mw/Mn=8.31).

Table 1 shows the contact angle against water and the thermaldecomposition starting temperature of the aliphatic polycarbonate resinsobtained in the Examples and Comparative Example. The term “Content (mol%)” in Table 1 indicates the content of the structural unit representedby the formula (1) based on the total number of moles of all structuralunits in the aliphatic polycarbonate resin. Further, the term“Fluorine-containing epoxide” in Table 1 indicates an epoxide used toform the structural unit represented by the formula (1).

TABLE 1 Thermal decom- position starting Contact temper- Content angleature Fluorine-containing epoxide (mol %) (°) (° C.) Example(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9- 1.0 98 219 1heptadecafluorononyl)oxirane Example 3-(3,3,4,4,5,5,6,6,7,7,8,8,8- 0.299 220 2 tridecafluorooctyloxy)-1,2- epoxypropane Example3-(3,3,4,4,5,5,6,6,7,7,8,8,8- 1.2 99 217 3 tridecafluorooctyloxy)-1,2-epoxypropane Compar- — — 68 215 ative Example 1

A comparison between Examples 1 to 3 and Comparative Example 1 revealsthat due to the introduction of a structure having a fluorine atom (X inthe formula (1)) into a side chain of the aliphatic polycarbonate resin,the contact angle against water was significantly improved, and thewater repellency was also improved.

Moreover, the thermal decomposition temperature was hardly increasedeven when such a structure was introduced. This indicates that thealiphatic polycarbonate resins can be burned away by the same heattreatment for general aliphatic polycarbonate resins.

The above results demonstrated that the aliphatic polycarbonate resinsof Examples 1 to 3 had excellent water repellency. It was indicated thatsuch aliphatic polycarbonate resins were suitable as, for example,materials for forming partitions.

INDUSTRIAL APPLICABILITY

The aliphatic polycarbonate resin according to the present invention haswater-repellent performance superior to that of conventional aliphaticpolycarbonate resins. For example, when a partition is formed using thealiphatic polycarbonate resin as a partition material, water-based inkis allowed to remain only in a desired portion with high accuracy.Therefore, the use of the aliphatic polycarbonate resin according to thepresent invention facilitates the formation of wiring substrates havinghighly controlled fine wiring etc., and the obtained wiring substratescan be incorporated into various electronic components etc.

The invention claimed is:
 1. An aliphatic polycarbonate resin comprisinga structural unit represented by the following formula (1):

wherein R¹, R², and R³ are each independently a hydrogen atom, a C₁-C₁₀alkyl group, or a C₆-C₂₀ aryl group; X is a substituent having afluorine atom; and R¹, R², and R³ may be the same or different; and astructural unit represented by the following formula (2):

wherein R⁴, R⁵, R⁶, and R⁷ are each independently a hydrogen atom, aC₁-C₁₀ alkyl group, or a C₆-C₂₀ aryl group; and R⁴, R⁵, R⁶, and R⁷ maybe the same or different, wherein the aliphatic polycarbonate resin hasa contact angle against water of 90° or more, and the content of thestructural unit represented by the formula (1) is 5 mol % or less basedon the total number of moles of all structural units, and the content ofthe structural unit represented by the formula (2) is 95 mol % or morebased on the total number of moles of all structural units.
 2. Thealiphatic polycarbonate resin according to claim 1, wherein X is a groupcontaining a trifluoromethyl group.
 3. The aliphatic polycarbonate resinaccording to claim 1, wherein the structural unit represented by theformula (1) is contained in an amount of 0.05 to 5 mol % based on thetotal number of moles of all structural units.
 4. The aliphaticpolycarbonate resin according to claim 1, which is an aliphaticpolycarbonate resin for partition formation.
 5. A partition materialcomprising the aliphatic polycarbonate resin according to claim
 4. 6. Asubstrate having a partition made of the aliphatic polycarbonate resinaccording to claim
 4. 7. A method for producing the substrate accordingto claim 6, the method comprising providing a coating film of apartition material comprising the aliphatic polycarbonate resin to forma partition.
 8. A method for producing a wiring substrate using thesubstrate according to claim 6, the method comprising providing a wiringmaterial on the substrate to form wiring.
 9. The method for producing awiring substrate according to claim 8, the method comprising forming agroove in the substrate, and providing a wiring material in the grooveto form wiring.
 10. A wiring forming method comprising forming wiringusing the partition material according to claim 5.